oh, and in reference to the above on head space:
- the ironwood beams stick down a little and you can get jammed up on them in some places if you make it 2m tall.
- stairs, you can hit your head on the stone floor over the stairs going down because stone is thick. A wood tile with a rug over it gives you back that 1 2x2 of floor space that otherwise would have to be a gap over the stairs.
- stone works a lot better with 3m high. I cannot advise 2m, if you want that you should be using wood.